Small Business Tax Deductions in Canada You’re Probably Missing

Every year, I meet business owners who’ve overpaid their taxes, not because they did anything wrong, but because nobody told them what they could legitimately claim. Deductions left unclaimed are just money handed to CRA that could have stayed with you.

Here are the deductions Canadian small business owners miss most often, and how to claim them without inviting a second look.

1. Home-office expenses

If you run your business from home, you can deduct a reasonable portion of rent or mortgage interest, utilities, and internet, based on the percentage of your home actually used for work. The key word is reasonable. A dedicated room used as an office? Absolutely. Claiming half your house because your laptop sits on the kitchen table? That’s how you get a letter.

2. Vehicle business use

If you use your vehicle for business, you can deduct the business-use portion of your costs, fuel, insurance, maintenance, and more. But CRA wants the business-use percentage, backed by a logbook. No log, no defence. Track your kilometres for one representative month and apply that ratio.

3. A share of your phone and internet

Most owners claim none of this, or all of it, which is worse. The business-use portion of your cell phone and home internet is deductible. Estimate it reasonably and keep it consistent.

4. Professional fees and subscriptions

Accounting and legal fees, business software, industry memberships, trade publications, and courses that maintain or improve your business skills are generally deductible. These add up quickly and are easy to forget.

5. Meals and entertainment (at 50%)

Business meals and entertainment are typically deductible at 50%. Keep the receipt and note who you met and why, the documentation is what makes the claim stick.

6. Bad debts

That invoice from a client who will never pay? Once it’s genuinely uncollectible, it can often be written off, reducing your taxable income. Don’t let it sit on your books pretending it’s an asset.

7. Salaries to family members who actually work

Paying a spouse or child who genuinely works in your business, at a fair market rate, is a legitimate way to split income across a household. The rules are strict: the work must be real and the pay reasonable. Done right, it’s smart planning. Done as a paper fiction, it’s a fast route to an audit.

8. Capital assets (the right way, at the right time)

Equipment, computers, and machinery generally aren’t deducted all at once, they’re claimed over time through capital cost allowance. But timing matters: an asset must be available for use by your year-end to start claiming it that year.

The rule behind all of them

Every deduction here shares one requirement: documentation. Your write-offs are only as strong as the records behind them. CRA can require the itemized receipt, a bank statement alone often isn’t enough, and you’re expected to keep records for six years. Photograph receipts as you go and you’ll never scramble.

The other truth: a fresh set of professional eyes usually finds deductions worth far more than the fee.

General information only. Deduction eligibility depends on your specific circumstances, confirm with a CPA before claiming.